Two halophilic archaeal strains, TRM20010(T) and TRM20345(T), were isolated from saline soil of the Lop Nur region in Xinjiang, north-west China. Cells from the two strains were pleomorphic rods, stained Gram-negative and produced red-pigmented colonies. Strains TRM20010(T) and TRM20345(T) were able to grow at 30-62 °C (optimum 37 °C), 0.9-5.1 M NaCl (optimum 2.6 and 3.4 M, respectively) and pH 6.0-10.0 (optimum pH 7.0-7.5) and neither strain required Mg(2+) for growth. The major polar lipids of the two strains were phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), two glycolipids chromatographically identical to galactosyl mannosyl glucosyl diether (TGD-1) and disulfated mannosyl glucosyl diether (S2-DGD). Phylogenetic analysis based on 16S rRNA and rpoB' genes revealed that strains TRM20010(T) and TRM20345(T) clustered together and formed a distinct clade separated from the related genera Halovivax, Haloterrigena, Halostagnicola, Natronolimnobius and Natrinema. The DNA G+C contents of strains TRM20010(T) and TRM20345(T) were 63.9 and 63.8 mol%, respectively. The DNA-DNA hybridization value between strain TRM20010(T) and strain TRM20345(T) was 42.8 %. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strains TRM20010(T) and TRM20345(T) represent two novel species in a new genus within the family Halobacteriaceae, for which the names Natribaculum breve gen. nov., sp. nov. (type strain TRM20010(T) = CCTCC AB2013112(T) = NRRL B-59996(T)) and Natribaculum longum sp. nov. (type strain TRM20345(T) = CCTCC AB2013113(T) = NRRL B-59997(T)) are proposed.
© 2015 Xinjiang Production & Construction Corps Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin/College of Life Science, Tarim University, Alar 843300, China.